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(1) Field of the Invention
The present invention relates to deicing and anti-icing compositions comprising a succinate salt and at least one freezing point depressant selected from the group consisting of monohydric alcohols, polyhydric alcohols, monomethyl or monoethyl ethers of polyhydric alcohols, and mixtures thereof. The compositions have enhanced ice-melting capacity compared to the ice-melting capacity of the succinate salt or the alcohol alone, particularly at temperatures below about xe2x88x9210xc2x0 C. The compositions are particularly useful as a windshield deicer/washer. Particular embodiments of the compositions are environmentally friendly.
(2) Description of Related Art
Windshield washer fluids generally consist of water, a water miscible alcohol to depress the freezing point, a surfactant for lubricating, and a colorant. In a typical windshield deicer/washer composition, the composition contains 22 to 35 wt % methanol with the balance being water, a small amount of a surfactant, and a small amount of colorant (U.S. Pat. No. 5,932,529 to Storey) . Other compositions containing heavier alcohols have been suggested (U.S. Pat. No. 5,043,088 to Falla and U.S. Pat. No. 5,772,912 to Lockyer et al.).
The desired characteristics for deicing or anti-icing compositions, in particular windshield deicer/washer compositions, are well known. The most important among these characteristics is the deicer""s ability to melt ice quickly. In addition, the windshield deicer/washer compositions should have a sufficiently low viscosity to xe2x80x9cwetxe2x80x9d the windshield fully without smearing or streaking and should be compatible with the materials comprising the windshield an its immediate surroundings. The wetting properties of the composition aid cleaning off dirt, grime, bug juice, bird droppings, and the like during warmer seasons.
A further consideration is the flammability of the windshield deicer/washer composition. Liquids that have a flash point below 37.8xc2x0 C. (1000xc2x0 F.) are considered flammable and liquids with a flash point above 37.80xc2x0 C. are considered combustible (U.S. Pat. No. 5,932,529 to Storey). Flammable liquids are considered more hazardous by the National Fire Protection Association, local fire marshals, the U.S. Department of Transportation, and the Occupational Safety and Health Administration. Consequently, flammable liquids are more regulated and have storage restrictions which require more secure containers. Therefore, it is desirable that a windshield deicer/washer compositions be classified as a combustible fluid and not a flammable fluid.
The following U.S. patents are examples of deicing or anti-icing compositions.
U.S. Pat. No. 5,043,088 to Falla discloses a deicing composition which consists essentially of one or more monohydric alcohols, one or more polyhydric alcohols, and one or more anionic fluorinated surfactants in combination. The composition is useful for removing ice from a surface such as an automobile windshield.
U.S. Pat. No. 5,772,912 to Lockyer et al. discloses aqueous, non-electrolytic, non-toxic, biodegradable, continuous single phase liquid anti-icing or deicing compositions. The compositions comprise water, a non-toxic freezing point depressant which includes particular monohydric or polyhydric alcohols, a thickener, and optionally a corrosion inhibitor.
U.S. Pat. No. 5,932,529 to Storey discloses windshield deicer/washer compositions that include 18 to about 33% by volume methanol, 1 to 14% by volume propylene glycol, and the balance water and preferably a surfactant and colorant. The composition has a flash point above 37.80xc2x0 C. which renders it a combustible fluid and not a flammable fluid.
The above deicer or anti-icing compositions all rely upon an alcohol, in particular methanol, to impart the ice-melting or ice-inhibiting properties to the compositions. While methanol is generally considered to be an effective deicer/anti-icer, other alcohols which are non-toxic, e.g., ethanol, are less effective. Furthermore, even though methanol is considered to be effective, its ice-melting capacity is limited. Therefore, there is a need for deicing and anti-icing compositions which have greater ice-melting capacities than those currently available. In particular, there is a need for deicing and anti-icing compositions which are non-toxic and which have an effective ice-melting capacity. Such compositions would be useful in windshield deicing and anti-icing compositions.
The present invention provides deicing and anti-icing compositions comprising a succinate salt and at least one freezing point depressant selected from the group consisting of monohydric alcohols, polyhydric alcohols, monomethyl or monoethyl ethers of polyhydric alcohols, and mixtures thereof. The compositions have enhanced ice-melting capacity compared to the ice-melting capacity of the succinate salt or the alcohol alone, particularly at temperatures below about xe2x88x92100xc2x0 C. The compositions are particularly useful as a windshield deicer/washer. Particular embodiments of the compositions are environmentally friendly.
Therefore, the present invention provides a composition which comprises in admixture (a) a succinate salt in an amount which acts to remove ice from a surface; and (b) at least one freezing point depressant selected from the group consisting of monohydric alcohols having 1 to 6 carbon atoms, polyhydric alcohols having 3 to 12 carbon atoms, monomethyl or monoethyl ethers of polyhydric alcohols having 3 to 12 carbon atoms, and mixtures thereof, wherein the admixture when mixed with water melts the ice more rapidly than either the succinate salt or the freezing point depressant alone.
In particular embodiments of the composition, the succinate salt is selected from the group consisting of potassium succinate (trihydrate), ammonium succinate (anhydrous), sodium succinate (hexahydrate), and combinations thereof.
In a further embodiments of the composition, the freezing point depressant is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, pentanol, and mixtures thereof. Preferably, the freezing point depressant is ethanol or the freezing point depressant is methanol or an admixture of the methanol and ethanol.
Preferably, the ratio of succinate salt to freezing point depressant in the composition is between about 1 to 10 to 10 to 1. More preferably, the ratio of succinate salt to freezing point depressant is 1 to 1.
In further embodiments of the composition, the composition further comprises the water in the admixture. Preferably, the composition comprises 20 to 30 wt % solids in solution with the water as the balance.
In further embodiments of the composition, the composition further comprises an organic surfactant which enables spreading of the composition on a glass surface, and a coloring agent.
In further embodiments of the composition, the composition in addition contains a glycol as an anti-icing agent.
In further embodiments of the composition, the composition in addition contains at least one corrosion inhibitor selected from the group consisting of an alkali metal polymer salt and magnesium succinate, an alkali metal polyaspartate and magnesium succinate, an alkali metal polysuccinimide, an alkali metal polyaspartate, and an alkali metal polymaleimide salt and magnesium succinate. In particular, wherein the alkali metal polymaleimide salt is sodium polymaleimide salt, the alkali metal polyaspartate is sodium polyaspartate, and the alkali metal polymaleimide salt is sodium polymaleimide salt.
The present invention also provides a method for deicing or anti-icing a surface which comprises applying a composition which comprises (a) an alkali metal succinate salt in an amount which acts to remove ice from a surface; and (b) at least one freezing point depressant selected from the group consisting of monohydric alcohols having 1 to 6 carbon atoms, polyhydric alcohols having 3 to 12 carbon atoms, monomethyl or monoethyl ethers of polyhydric alcohols having 3 to 12 carbon atoms, and mixtures thereof, wherein the composition melts ice formed on the surface more rapidly than either the succinate salt or the freezing point depressant alone.
In particular embodiments of the method, the succinate salt is selected from the group consisting of potassium succinate (trihydrate), ammonium succinate (anhydrous), sodium succinate (hexahydrate), and combinations thereof.
In a further embodiments of the method, the freezing point depressant is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, pentanol, and mixtures thereof. Preferably, the freezing point depressant is ethanol or the freezing point depressant is methanol or an admixture of the methanol and ethanol.
Preferably, the ratio of succinate salt to freezing point depressant in the composition is between about 1 to 10 to 10 to 1. More preferably, the ratio of succinate salt to freezing point depressant is 1 to 1.
In further embodiments of the method, the composition further comprises the water in the admixture. Preferably, the composition comprises 20 to 30 wt % solids in solution with the water as the balance.
In further embodiments of the method, the composition further comprises an organic surfactant which enables spreading of the composition on a glass surface, and a coloring agent. In particular embodiments, the surface to which the composition is applied is a glass in a vehicle, particularly, wherein the surface is a glass windshield of a vehicle with wipers and wherein the composition contains an organic surfactant for spreading the composition on the glass, optionally a glycol for removing ice, and optionally a coloring agent.
In further embodiments of the method, the composition in addition contains a glycol as an anti-icing agent.
In further embodiments of the method, the composition in addition contains at least one corrosion inhibitor selected from the group consisting of an alkali metal polymer salt and magnesium succinate, an alkali metal polyaspartate and magnesium succinate, an alkali metal polysuccinimide, an alkali metal polyaspartate, and an alkali metal polymaleimide salt and magnesium succinate. In particular, wherein the alkali metal polymaleimide salt is sodium polymaleimide salt, the alkali metal polyaspartate is sodium polyaspartate, and the alkali metal polymaleimide salt is sodium polymaleimide salt.
The present invention further provides a composition packaged for use as a windshield wiper fluid which comprises in admixture (a) a succinate salt in an amount which acts to remove ice from a surface; and (b) at least one freezing point depressant selected from the group consisting of monohydric alcohols having 1 to 6 carbon atoms, polyhydric alcohols having 3 to 12 carbon atoms, monomethyl or monoethyl ethers of polyhydric alcohols having 3 to 12 carbon atoms, and mixtures thereof, wherein the composition melts ice.
In particular embodiments of the composition, the succinate salt is selected from the group consisting of potassium succinate (trihydrate), ammonium succinate (anhydrous), sodium succinate (hexahydrate), and combinations thereof.
In a further embodiments of the composition, the freezing point depressant is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, pentanol, and mixtures thereof. Preferably, the freezing point depressant is ethanol or the freezing point depressant is methanol or an admixture of the methanol and ethanol.
Preferably, the ratio of succinate salt to freezing point depressant in the composition is between about 1 to 10 to 10 to 1. More preferably, the ratio of succinate salt to freezing point depressant is 1 to 1.
In further embodiments of the composition, the composition further comprises the water in the admixture. Preferably, the composition comprises 20 to 30 wt % solids in solution with the water as the balance.
In further embodiments of the composition, the composition further comprises an organic surfactant which enables spreading of the composition on a glass surface, and a coloring agent.
In further embodiments of the composition, the composition in addition contains a glycol as an anti-icing agent.
In further embodiments of the composition, the composition in addition contains at least one corrosion inhibitor selected from the group consisting of an alkali metal polymer salt and magnesium succinate, an alkali metal polyaspartate and magnesium succinate, an alkali metal polysuccinimide, an alkali metal polyaspartate, and an alkali metal polymaleimide salt and magnesium succinate. In particular, wherein the alkali metal polymaleimide salt is sodium polymaleimide salt, the alkali metal polyaspartate is sodium polyaspartate, and the alkali metal polymaleimide salt is sodium polymaleimide salt. OBJECTS
Therefore, it is an object of the present invention to provide deicing and anti-icing compositions which have greater ice-melting capacities than those currently available.
It is also an object of the present invention to provide deicing and anti-icing compositions which are non-toxic and which have an effective ice-melting capacity.